Space shuttle - what would you do?
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No, but the tiles are so fragile that NASA is afraid of having more of them damaged if a repair was attempted. It seems to me that they should have found a way to eliminate the problem before sending any more people up in the shuttle. I wonder if they have tried reinforcing the foam on the tanks with a strong netting, maybe just under the surface of the foam, of something like Kevlar (or something better; what do I know from fibers?)so that the foam coating would have more integrity under stress. I don't know much about this because it is, after all, rocket science.
First off, I don't even like to fly, so going into outer space doesn't even register on my radar. Now, for what I heard on NPR on the way home from Mankato, today:
1) NASA took some damaged tiles and put them in a blast furnace to mimic the heat they'd endure during re-entry. Those tests showed the aluminum skin underneath did not reach 350-degrees, which is its critical melting point.
2) The 100-ft. 'repair arm' is cumbersome, and astronauts in 300-lb. space suits would find themselves bouncing up and down a lot---they used the analogy of how a person at the end of a diving board bounces. If the Shuttle Repairperson should bump into the tiles, they'd probably do even more damage.
3) The repair goo they have with them has not been tested in space, so they aren't sure how it will react. If their tests showed the aluminum skin beneath the heat tiles would exceed 350-degrees, they'd risk the repair.
THEREFORE: NASA decided they'd go with the demon they know, rather than risk ones they don't know. Since they know more about it than I do, I'm going to withhold my 2-cents and hope those crazy astronauts get back safely.
1) NASA took some damaged tiles and put them in a blast furnace to mimic the heat they'd endure during re-entry. Those tests showed the aluminum skin underneath did not reach 350-degrees, which is its critical melting point.
2) The 100-ft. 'repair arm' is cumbersome, and astronauts in 300-lb. space suits would find themselves bouncing up and down a lot---they used the analogy of how a person at the end of a diving board bounces. If the Shuttle Repairperson should bump into the tiles, they'd probably do even more damage.
3) The repair goo they have with them has not been tested in space, so they aren't sure how it will react. If their tests showed the aluminum skin beneath the heat tiles would exceed 350-degrees, they'd risk the repair.
THEREFORE: NASA decided they'd go with the demon they know, rather than risk ones they don't know. Since they know more about it than I do, I'm going to withhold my 2-cents and hope those crazy astronauts get back safely.
At least the tile is not on the leading edge of a wing like in the last disaster.
At least the tile is not on the leading edge of a wing like
That is an encouraging thought. But given the opportunity
(resource availability), I think I would want to take an
extended vacation (or extended work schedule) on the space
station and wait for the next ride home.
What's the point of taking "repair goo" with them if they
aren't going to use it (or at least perform some sort of
non-threatening test with it as long as they're up there?)
I'll be fearing for them all the way down.
That is an encouraging thought. But given the opportunity
(resource availability), I think I would want to take an
extended vacation (or extended work schedule) on the space
station and wait for the next ride home.
What's the point of taking "repair goo" with them if they
aren't going to use it (or at least perform some sort of
non-threatening test with it as long as they're up there?)
I'll be fearing for them all the way down.
350-degrees, which is its critical melting point.
Maybe the aluminum on the shuttle is different, but the melting point of everyday aluminum is 660C, or 1220F. If it were 350F, one would not be able to use aluminum baking pans in the typical home oven.
Otherwise your list sounds quite reasonable. I also wondered about the risks of dangling the repair-naut on the end of that long boom, on the underside of the shuttle, with no direct ability of the people inside the shuttle to see what's going on. I just hope the scientists are correct that the shuttle can land safely with that gash in its ventral covering.
Maybe the aluminum on the shuttle is different, but the melting point of everyday aluminum is 660C, or 1220F. If it were 350F, one would not be able to use aluminum baking pans in the typical home oven.
Otherwise your list sounds quite reasonable. I also wondered about the risks of dangling the repair-naut on the end of that long boom, on the underside of the shuttle, with no direct ability of the people inside the shuttle to see what's going on. I just hope the scientists are correct that the shuttle can land safely with that gash in its ventral covering.
Sudsmaster----I wondered about the 350-degree melting point, too. But they did say aluminum 'skin', so I thought maybe that made a difference. And I'm sure an aluminum pan gets much hotter than 350-degrees sitting over high heat on a range burner. Or maybe I misunderstood, and they meant they didn't feel safe if the aluminum skin got any hotter than 350-degrees.
350 degrees could be the point where the aluminum loses its strength.A pan with food in it would be diffrent since the food is absorbing the heat-the pot is transfering the heat to the food.
Um, I'd have to check into that, but I don't *think* most aluminum alloys would start losing strength at 350F.
The article may have been referring to the felt, which probably would start to fail at around 350F. If it's synthetic, it makes sense it might start to melt around that temp.
Are we sure the article was talking about F and not C?
The article may have been referring to the felt, which probably would start to fail at around 350F. If it's synthetic, it makes sense it might start to melt around that temp.
Are we sure the article was talking about F and not C?
mayken4now
Well-known member
Quit going to space and spending all that damn money. my .02 cents
Steve
Steve
jasonl
New member
Amen Steve!
Space and the moon is inhabitable, so why bother.
Space and the moon is inhabitable, so why bother.
63getelevision
Well-known member
- Joined
- Jun 26, 2007
- Messages
- 533
Stop the program and replace all the defective parts in the damn thing, before they kill more innocent people.
The problem, I've read, isn't the aluminum, but rather the RTV adhesive that holds the tiles on. At around 350 degrees, it stops holding. Of course, this means the tile could pop off, or a whole bunch could. Exposing a large area to heat. Melt and bye bye shuttle.
I'd take the extended vacation, too. And return home on the much more proven Russian ship...
In any case, NASA claims this isn't a huge issue, but they're studying it like crazy anyway. But NASA's credibility on anything safety related is zero, at best, since the shuttle program started.
I do find it interesting that the most complex machine ever built can be downed by hitting it with what amounts to a NERF bat...
I'd take the extended vacation, too. And return home on the much more proven Russian ship...
In any case, NASA claims this isn't a huge issue, but they're studying it like crazy anyway. But NASA's credibility on anything safety related is zero, at best, since the shuttle program started.
I do find it interesting that the most complex machine ever built can be downed by hitting it with what amounts to a NERF bat...
jmirawm
Well-known member
I would.........
GET DRUNK !
GET DRUNK !
Or isn't it all pretty
My bad...
Was watching a program on American aircraft industry, and learned that aircraft aluminum loses 1/2 its strength at 350F.
Was watching a program on American aircraft industry, and learned that aircraft aluminum loses 1/2 its strength at 350F.
The terminal part of the landing is flown by hand. There is auto-land software in the computers, but it's never been tested in actual flight.
The wing leading edge material that caused the STS-107 accident was not a tile. The leading edges get so hot that tiles won't work, and anyway it's hard to make them to fit the curvature of the wing edge. They use a different material called RCC. It's molded in one big piece rather than being in a lot of little chunks like the tiles are. The foam chunk that damaged it was a heck of a bigger hit than a Nerf ball. First of all, the foam is denser than that -- it's more like that stuff that is used for house insulation. Second, it was a chunk the size of a suitcase. Third, it was moving at 400 MPH.
The foam was a problem in the early history of the Shuttle program, but fine tuning of the formula and the methods of applying it had pretty much licked the problem by 1991. Then, about six years ago, the EPA made NASA change the formula and use a different solvent for spraying the foam. The new solvent made the foam more brittle and less able to take vibration.
The Shuttle insulation is based on the best technology that was available in the mid-'70s. I know a couple of people who think that now, a new spacecraft could be built that would use metal shielding and not weigh any more than the tiles/blankets/foam do, with the assumption that the spacecraft flies a less aggressive re-entry profile. This relies on two things that weren't available in 1975: advanced high-temperature metal alloys, and computing power to fly a more complex re-entry.
I spent four years working on STS-107. I met the astronauts and I worked in Mission Control during that flight. I was involved in the accident investigation.
The wing leading edge material that caused the STS-107 accident was not a tile. The leading edges get so hot that tiles won't work, and anyway it's hard to make them to fit the curvature of the wing edge. They use a different material called RCC. It's molded in one big piece rather than being in a lot of little chunks like the tiles are. The foam chunk that damaged it was a heck of a bigger hit than a Nerf ball. First of all, the foam is denser than that -- it's more like that stuff that is used for house insulation. Second, it was a chunk the size of a suitcase. Third, it was moving at 400 MPH.
The foam was a problem in the early history of the Shuttle program, but fine tuning of the formula and the methods of applying it had pretty much licked the problem by 1991. Then, about six years ago, the EPA made NASA change the formula and use a different solvent for spraying the foam. The new solvent made the foam more brittle and less able to take vibration.
The Shuttle insulation is based on the best technology that was available in the mid-'70s. I know a couple of people who think that now, a new spacecraft could be built that would use metal shielding and not weigh any more than the tiles/blankets/foam do, with the assumption that the spacecraft flies a less aggressive re-entry profile. This relies on two things that weren't available in 1975: advanced high-temperature metal alloys, and computing power to fly a more complex re-entry.
I spent four years working on STS-107. I met the astronauts and I worked in Mission Control during that flight. I was involved in the accident investigation.
What will the replacement for the shuttle be like? Will we return to ballistic missile type rocket vehicles, with space capsules (like the Russians use)? Or another flying craft like the shuttle, but with a simpler design?
Thanks fa_f3_20 . . .
for such a nice, concise, and factual answer. Given the much-publicized troubles of the space shuttle, it is easy to forget that it is a remarkable vehicle, the first of its kind, and has performed very well in many respects.
for such a nice, concise, and factual answer. Given the much-publicized troubles of the space shuttle, it is easy to forget that it is a remarkable vehicle, the first of its kind, and has performed very well in many respects.
